I am not as enthusiastic as you about "modern molecular methods" (in fact,
I cannot support any "monotheistic" approach to systematics). Certainly,
they (sometimes) yield new characters for comparison but you should not
forget that selection acts upon the phenotype (i.e. something which is at
the best indirectly influenced by the genotype, or not at all in the case
of pseudogenes). A phylogenetic reconstruction exclusively based on
sequence comparison or molecular data is in my opinion pure waste of time &
money. The phenotype *must* be considered in the first line, other data can
be used for confirmation, never as the basis of a phylogeny.
>One of the
>interesting result was that Roridula is sister to Darlingtonia,
>Sarracenia, and Heliamphora. Another is that Byblis is close to
>Pinguicula and Utricularia and VERY far from Cephalotus, with which it is
>often placed.
This is rather exactly the kind of short-sighted implications which are the
greatest danger of "modern molecular methods". In fact, the mentioned data
only suggest that _Roridula_ belongs to a huge and probably heterogeneous
complex of many loosely related families (something like Corniflorae) of
low-intermediate "advancedness" (if something like this does exists), the
Sarraceniaceae being (+/-) associated to the same clump but very probably
from a rather radically different end.
_Byblis_ on the other hand, is placed near Solaniflorae, which means that
it is in fact more closely related to potatoes and only very remotely so to
the "clade" including Lentibulariaceae (viz. Lamiiflorae).
> The Drosera called my attention the most. First of all,
>they really are close to Nepenthes.
This is not new but probably wrong in this oversimplified statement (well,
they are of course both dicotyledons...). Furthermore, the most interesting
families in this respect (viz. Dioncophyllaceae and Ancistrocladaceae) have
not been considered.
> Second, Drosophyllum stems off from
>Drosera before Dionaea and the first Drosera to stem off is D.regia.
This is not at all new, and even purely morphological comparison indicates
this. Again, important species (e.g. _D.meristocaulis_) have not been
considered at all.
> The
>Drosera then split into 2 groups. In one of these D.burmanni stems to one
>side while D.capensis and D.filiformis stem to the other. In the other
>group, D.binata and D.peltata stem to one side while D.petiolaris and
>D.dichrosepala stem to the other.
These data support some (much older) hypotheses. The hypothesis of a
relationship between _D.binata_/_D.peltata_ and the _D.petiolaris_ group or
of a close relationship (closer than to sect.Drosera) between the latter
and _D.dichrosepala_ should be checked more properly because it contradicts
morphological classification.
>I'd mentioned that a thick-rooted species like D.binata probably
>originated the tuberous Drosera while D.petiolaris and the pygmies must
>be closely related groups, due to certain morphological similarities
>(like small lamina and long, narrow petioles, present in most species).
I am happy to see you are eventually returning to comparative morphology.
So there remains some hope for me. Your first hypothesis is not as highly
speculative as you have stated, I think. But the "pygmies" need not at all
be closely related to the _D.petiolaris_-complex. In fact, I consider them
to be rather remote (no gemmae formed in the latter, styles never divided
vs. always multifid, the first confined to subtropical S AU to N.Zeal., the
latter from tropical AU to N.Guin., caryological differences).
Kind regards
Jan